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In response to Decision Theory FAQ
Comment author: incogn 28 February 2013 05:33:54PM *  9 points [-]

I don't really think Newcomb's problem or any of its variations belong in here. Newcomb's problem is not a decision theory problem, the real difficulty is translating the underspecified English into a payoff matrix.

The ambiguity comes from the the combination of the two claims, (a) Omega being a perfect predictor and (b) the subject being allowed to choose after Omega has made its prediction. Either these two are inconsistent, or they necessitate further unstated assumptions such as backwards causality.

First, let us assume (a) but not (b), which can be formulated as follows: Omega, a computer engineer, can read your code and test run it as many times as he would like in advance. You must submit (simple, unobfuscated) code which either chooses to one- or two-box. The contents of the boxes will depend on Omega's prediction of your code's choice. Do you submit one- or two-boxing code?

Second, let us assume (b) but not (a), which can be formulated as follows: Omega has subjected you to the Newcomb's setup, but because of a bug in its code, its prediction is based on someone else's choice than yours, which has no correlation with your choice whatsoever. Do you one- or two-box?

Both of these formulations translate straightforwardly into payoff matrices and any sort of sensible decision theory you throw at them give the correct solution. The paradox disappears when the ambiguity between the two above possibilities are removed. As far as I can see, all disagreement between one-boxers and two-boxers are simply a matter of one-boxers choosing the first and two-boxers choosing the second interpretation. If so, Newcomb's paradox is not as much interesting as poorly specified. The supposed superiority of TDT over CDT either relies on the paradox not reducing to either of the above or by fiat forcing CDT to work with the wrong payoff matrices.

I would be interested to see an unambiguous and nontrivial formulation of the paradox.

Some quick and messy addenda:

  • Allowing Omega to do its prediction by time travel directly contradicts box B contains either $0 or $1,000,000 before the game begins, and once the game begins even the Predictor is powerless to change the contents of the boxes. Also, this obviously make one-boxing the correct choice.
  • Allowing Omega to accurately simulate the subject reduces to problem to submit code for Omega to evaluate; this is not exactly paradoxical, but then the player is called upon to choose which boxes to take actually means the code then runs and returns its expected value, which clearly reduces to one-boxing.
  • Making Omega an imperfect predictor, with an accuracy of p<1.0 simply creates a superposition of the first and second case above, which still allows for straightforward analysis.
  • Allowing unpredictable, probabilistic strategies violates the supposed predictive power of Omega, but again cleanly reduces to payoff matrices.
  • Finally, the number of variations such as the psychopath button are completely transparent, once you decide between choice is magical and free will and stuff which leads to pressing the button, and the supposed choice is deterministic and there is no choice to make, but code which does not press the button is clearly the most healthy.
In response to comment by incogn on Decision Theory FAQ
Comment author: Amanojack 03 March 2013 05:21:10AM *  2 points [-]

I agree; wherever there is paradox and endless debate, I have always found ambiguity in the initial posing of the question. An unorthodox mathematician named Norman Wildberger just released a new solution by unambiguously specifying what we know about Omega's predictive powers.

Comment author: shminux 10 May 2012 03:47:21PM *  1 point [-]

Anti-epistemology is a huge actual danger of actual life,

So it is, but I'm wondering if anyone can suggest a (possibly very exotic) real-life example where "epistemic rationality gives way to instrumental rationality."? Just to address the "hypothetical scenario" objection.

EDIT: Does the famous Keynes quote "Markets can remain irrational a lot longer than you and I can remain solvent." qualify?

Comment author: Amanojack 10 May 2012 06:49:01PM 3 points [-]

Any time you have a bias you cannot fully compensate for, there is a potential benefit to putting instrumental rationality above epistemic.

One fear I was unable to overcome for many years was that of approaching groups of people. I tried all sorts of things, but the best piece advice turned out to be: "Think they'll like you." Simply believing that eliminates the fear and aids in my social goals, even though it sometimes proves to have been a false belief, especially with regard to my initial reception. Believing that only 3 out of 4 groups will like or welcome me initially and 1 will rebuff me, even though this may be the case, has not been as useful as believing that they'll all like me.

Comment author: Vladimir_Nesov 07 May 2012 08:52:29PM *  13 points [-]

With minus 373 Karma points for the last 30 days under your belt, I think you should take a hint and stop posting. If this comment is upvoted/not convincingly disputed (by others), I'm going to start removing some of the worse comments you make in the near future.

Comment author: Amanojack 08 May 2012 08:37:11PM *  4 points [-]

He's making some interesting points, and he gets extra credit in my view for taking so radical a view while usually remaining reasonable. I find his railing against prediction to be puzzling, but his semantic points and discussion of Ptolemaic explanations have given me a lot to think about.

I also noticed that even some of his friendly, reasoned posts were being downvoted to the same extreme negative levels, which seems unwarranted. He has posted too much without familiarizing himself with the norms here, but he shows sincerity and willingness to learn and adapt. He got a little testy a few times, but he also apologized a lot.

All in all, with a few notable exceptions, it looks like he is getting downvoted mainly for unfamiliarity with LW posting style and for disagreeing with "settled science" (I myself am not too partial to that term). Perhaps also for some unconventional spellings and other idiosyncrasies.

I'm open to being corrected on this, but I think I have read this entire thread and I am pretty sure Monkeymind is not deliberately trolling. High inferential distance feels like trolling so often that it's almost a forum trope. I myself am enjoying some of his posts and the responses.

I'll change my mind if he continues with the present posting style, though.

Comment author: Monkeymind 02 May 2012 03:54:16PM *  -2 points [-]


Comment author: Amanojack 08 May 2012 08:08:39PM *  1 point [-]

You're making a ton of interesting points, but please succinctify (a lot!). I mean, let people reply and stuff. I feel sorry for you writing all that knowing almost no one will see it. It's obvious you're reading LW classic posts and making discoveries, and then immediately turning around and applying them, which is great. I just think you'd do well to steep yourself in the posting norms of this forum so you can participate in a more fruitful way. Again, I for one would like to hear well-reasoned radical views.

Comment author: Vaniver 14 April 2012 12:34:18AM 0 points [-]

Hypotheses describe and theories explain. If they don't make sense they are worthless!

Theories don't explain- they predict. Consider gravity- Newton's law tells you the attraction between two masses, and it's mostly consistent with the mostly elliptical orbits that we observe the planets moving in.

But why does gravity exist? Why does it take that particular form? The theory is silent. It tells you how things will behave, but offers no further explanation.

If you can tell me how anything can have 0 dimensions in reality

So, electrons have mass, and charge, but as far as we can tell their radius is indistinguishable from zero. Does that count as 0 dimensions for you?

Comment author: Amanojack 08 May 2012 07:32:44PM *  0 points [-]

Theories don't explain- they predict. Consider gravity- Newton's law tells you the attraction between two masses, and it's mostly consistent with the mostly elliptical orbits that we observe the planets moving in.

The gravitational equation is effectively just* a summary of the observed data, so it is no surprise that it predicts. I believe Monkeymind finds this unsatsifactory, but I'm still not sure exactly how. Perhaps he defines theory differently. I'm a little curious what actually causes the Earth to pull on me, rather than, say, push me away. At the time Newton said he had no hypothesis for that, but now the same equation constitutes a theory or explanation? I feel like these terms are used a little too loosely.

*Not to imply that finding the equation that fit the data wasn't an important achievement

Comment author: Swimmer963 13 April 2012 10:57:14PM *  2 points [-]

If someone says that square circles exist and they have the math to prove it, do I need to check their math?

If someone had a theory that made useful predictions about the behaviour of reality, and could be used to make cool technology like transistors, and the only way you could get it to work and give those predictions was to assume the existence of hypothetical, mathematical square circles, who are you to call that theory "wrong" or "false"? The universe isn't obligated to be easy for us to understand, any more than it's obligated to be easy to understand for a mouse.

Comment author: Amanojack 08 May 2012 07:26:20PM -1 points [-]

I would say the theory was poorly communicated, at best.

Comment author: thomblake 13 April 2012 07:33:55PM 7 points [-]

Reality is about what is real. Objects are real. They are made of matter (atoms) they have shape and location. Amplitudes, configurations,laws and flow are not real. They are not objects they are what objects do.

I understand why you think so, since your species evolved with sensors that work at a particular macro level, and so intuitively you expect everything in reality to work the same way. It does not make sense to you that the same rules don't apply if you go really really fast, or if you're looking at something really really big or really really tiny, or if you're observing a process over a very short or very long time scale.

Sadly, this is a design flaw in your brain. You will not likely be able to rework your intuitions so that reality always "makes sense". Reality doesn't have to conform to your preconceptions, and your brain just isn't made to radically transform itself like that.

Luckily, you can choose to use a mechanism other than human intuition to understand the universe. Like mathematics, which seems to do a much better job, even in a way observable to humans. We have lots of devices (observable at human scales!) that do exactly what the mathematics said they would, like GPS.

But despair not! It's not completely a lost cause. Even though we are not made to understand things directly using math all the time, there are ways of retraining your intuitions to some extent, and correcting for your design flaws in other ways where that's not possible. Figuring out how to do that is the primary mission of this site.

Comment author: Amanojack 08 May 2012 07:01:12PM -1 points [-]

Luckily, you can choose to use a mechanism other than human intuition to understand the universe. Like mathematics, which seems to do a much better job, even in a way observable to humans. We have lots of devices (observable at human scales!) that do exactly what the mathematics said they would, like GPS.

I think there is a common miscommunication on this point. If something cannot be understood in the conventional human sense, can it be understood via math? It depends on what we mean by "understand." We can certainly catalog what we observe and summarize those data in the form of mathematical formulae and models.

However, if those are merely very succinct summaries, it is no surprise that they make accurate predictions, as they would effectively just be extrapolating from the observed data. It also seems unsatisfying to call that a theory in the traditional sense, if it is really more like curve-fitting.

Comment author: Mitchell_Porter 16 April 2012 02:32:21AM 7 points [-]

I did mean you, specifically. Learning QM has been compared to learning to ride a bicycle. You don't do that by first defining your terms, you just get out there and do it, and it's hard to reduce the knowledge of how to ride a bike to definitions. When people learn QM, they slide past some difficulties of logic, and are "rewarded" with the ability to quantitatively describe and predict atomic behavior.

There is a huge spectrum of attitudes among physicists towards the logical or conceptual basis of QM. On this site, they want to make sense of QM by adopting a radical new picture of reality in which there are "flows" of "amplitude-stuff" through the hyperspace of parallel universes. This is a genuine faction of opinion among physicists. But then you have the more down-to-earth people who tell you that quantum physics is just like classical physics, except that everything is a little "fuzzy" or "uncertain". This view is something of a philosophical placebo which allows its adherents to feel that there is no conceptual problem in QM.

Regarding even more basic matters, like what's going on in the very first steps towards the mathematization of physical concepts, that is a discussion that interests me, but we would first need to agree on exactly what the "issues" are, which might take a while. So I think we should have it privately, and then report back to the site, rather than flailing around in public. My mail is mporter at gmail.com, please contact me there if you want to continue this dialogue.

Comment author: Amanojack 08 May 2012 06:48:14PM *  0 points [-]

Learning QM has been compared to learning to ride a bicycle. You don't do that by first defining your terms, you just get out there and do it, and it's hard to reduce the knowledge of how to ride a bike to definitions.

This may indeed be the case, but taking the outside view - if I didn't know you were talking about QM, but knew it was about some purported scientific theory - giving a free pass to the usual strict rationalist requirement to "define your terms clearly" would seem pretty dubious. There are a lot of ways to build whole systems out of equivocations and other such semantic fudging, a lot of religious argument operates that way, and so on.

Torture Simulated with Flipbooks

9 Amanojack 26 May 2011 01:00AM

What if the brain of the person you most care about were scanned and the entirety of that person's mind and utility function at this moment were printed out on paper, and then several more "clock ticks" of their mind as its states changed exactly as they would if the person were being horribly tortured were printed out as well, into a gigantic book? And then the book were flipped through, over and over again. Fl-l-l-l-liiiiip! Fl-l-l-l-liiiiip!

Would this count as simulated torture? If so, would you care about stopping it, or is it different from computer-simulated torture?

Comment author: Peterdjones 25 May 2011 11:25:29PM 0 points [-]

As for this collectivism, though, I don't go for it. There is no way to know another's utility function, no way to compare utility functions among people, etc. other than subjectively.

That's very contestable. It has frequently argued here that preferences can be inferred from behaviour; it's also been argued that introspection (if that is what you mean by "subjectively") is not a reliable guide to motivation.

Comment author: Amanojack 26 May 2011 12:42:29AM 0 points [-]

This is the whole demonstrated preference thing. I don't buy it myself, but that's a debate for another time. What I mean by subjectively is that I will value one person's life more than another person's life, or I could think that I want that $1,000,000 more than a rich person wants it, but that's just all in my head. To compare utility functions and work from demonstrated preference usually - not always - is a precursor to some kind of authoritarian scheme. I can't say there is anything like that coming, but it does set off some alarm bells. Anyway, this is not something I can substantiate right now.

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